Update: I was unfortunately not aware of Shamus Young's severe criticism of Fallout 3 available here to link in the original piece and I regret that. It dovetails rather nicely with what I've written and it's much better executed than my piece. I strongly recommend anyone...

Command and Conquer 64 Cheats

Command and Conquer 64

N64

Cheat Mode:
At the title screen press B, A, R, R, A, C-Right, Up, Down, A. Select Replay
Mission option at the main menu, then press L to show all missions and R to
choose your team.

Start battle after enabling the code. Press L + R to show programming debug
sceen. Press R + L + Up for an automatic win or R + L + Down for an automatic
loss.

Zoom:
Hold L press C-Up or C-Down to zoom in and out of the battlefield.

Easy Construction:
From the toolbar, highlight a unit to be created then press A. Hold Z and press
A again after receiving the "Unit Ready" or "Construction Complete" message
to build the same unit again without returning to the toolbar.